WORCESTER— One of three men awaiting trial on murder charges in the 1994 disappearance of Kevin Harkins pleaded not guilty today to a charge of soliciting the murder of a witness in the Harkins case.

John R. Fredette, 50, of Saco, Maine, was indicted March 22 on a solicitation to murder charge involving an allegation that in January of this year, while in custody at the Worcester County Jail and House of Correction in West Boylston, Mr. Fredette tried to hire a fellow inmate, Raymond Amis, to kill an unnamed individual.

While proseecutors have not identified the target of the alleged murder plot, Timothy J. Connolly, a spokesman for District Attorney Joseph D. Early Jr., confirmed last week that the individual is a potential prosecution witness in the Harkins slaying.

Mr. Fredette and two co-defendants, Matteo Trotto and Elias Samia, were indicted last year on murder charges in the death of Mr. Harkins. Police and prosecutors say the 36-year-old was last seen on Feb. 15, 1994, leaving Suney's Pub on Chandler Street with Mr. Trotto.

While his body has never been found, in 2008 Mr. Harkins was officially declared dead in Worcester Probate and Family Court.

Prosecutors allege that Mr. Harkins was shot while in a car with Mr. Trotto, Mr. Fredette and Mr. Samia days after reneging on an agreement to provide false testimony during Mr. Fredette's 1994 trial on drug charges. .